Energetic materials such as the nitro ester/nitramines described in this invention record are utilized in the production of gun and rocket propellants. Propellants differ from explosives primarily in regard to their burning rates. Many propellants utilize explosives such as nitroglycerine or a mixture of explosives with various modification agents. There has been a need for a replacement for nitroglycerin in making gun propellants. It has been desired to achieve a nitroglycerin replacement with lower vulnerability, primarily to initiation. It has been desired to produce a low vulnerability (LOVA) propellant which is significantly less sensitive to initiation than standard nitro ester propellants while maintaining a low freezing point.
The freezing point of a compound used in formulation of a propellant is of importance. A lower freezing point is desirable because it prevents or minimizes crystallization of the propellant mixture when subjected to cold weather. However, few compounds with low freezing points possess desired explosive properties. Thus, there has been a need to provide a material that will easily form colloidal mixtures with nitrocellulose, have a low freezing point, is less sensitive to handle than nitroglycerin, but yet has comparable energy qualities or impetus to nitroglycerin.
NENA (nitrate ethyl nitramines) compounds have been explored as possible nitroglycerin replacements. They are hybrid molecules which Contain a nitro ester group (as in nitroglycerin) and a nitramine group (as in HMX or RDX). These compounds are less sensitive to impact and friction than nitroglycerin and some have a lower freezing point than nitroglycerin. However, typically colloidal mixtures of the NENA compounds with nitrocellulose exhibit a lower impetus than those of nitroglycerin with nitrocellulose. Various NENA compounds and processes for producing them are disclosed in U.S. Pat. Nos. 2,485,855 and 2,678,946. U.S. Pat. No. 2,461,582 discloses a series of nitroxyalkyl nitramines and a method for their preparation and purification. In particular this patent discloses dinitroxydiethyl nitramine commonly called DINA. The patent reveals the use of DINA in nitrocellulose colloids.
U.S. Pat. No. 4,381,958 discloses propellant compositions containing triaminoguanidene nitrate (TAGN) as an oxidizer and a liquid energetic plasticizer-binder to improve thermal stability when used with resorcinol. The patent also discloses use of NENA as a plasticizer component.
U.S. Pat. No. 4,450,110 discloses azido nitramine 1,5-diazido-3 nitrazapentane (DIANP) and its use in gun and rocket propellants. The DIANP was prepared by first preparing a solution of DINA.
The present invention relates to a composition formed by admixture of compounds to provide low freezing point and yet provide good impetus in the formulation of propellants from the mixtures.